Shock absorber



May 5, 1953 w. G. PATRIQUIN SHOCK ABSORBER Filed Aug.,5l 1951 IN VEN TOR. W/L L /AM 6. PAM/amv the shock absorber while said portion of the lowerV member I5 faces the opposite end of the shock absorber. The cup-shaped portions I6 of the two members I5 are of such external-diameter as to slidably interiit with the interior of the working cylinder I I. The cup-shaped portions I6 on their peripheries are provided with a plurality of .cir-

cularly spaced axially extending and circularly portion I3a of the piston rod and by the lugs 23 and the inner circumferences of the shoulders 22 of the member I5. Sleeve-like valves 30 are slidable on the reduced portion I3a of the piston rod within the sleeve 'portions 2I of the members I5 and said sleeve-like valves have radially outwardly extending anges 30a which seat against the shoulders 22, it being noted that when said sleeve-like valves 30 have their flanges 30a seated as just referred to, said valves close communication through the passages 29 with the interior of the sleeve portions 2 I. Coil springs 3l abut the inner sides of the disks I4 and 20 and s the nanges 30a of the sleeve valves 30 and norelongated grooves I1 which, with Athe inner wall of the working cylinder II, provide passageways forthe iiow of oil therethrough. .The cup-shaped portions I6 also are provided on their interior circumferences with a plurality of circularly spaced axially extending grooves I8 which are staggered relative to the grooves I1 as clearly indicated in Fig. 4. The grooves I8 at their inner ends communicate with radial grooves I9 formed in the bottoms of the cup-shaped portions I6. The disk 'I4 interiits the interior yof the cupshaped. portion I6 of the upper member I5 as does also a disk with respect tothe cup-shaped portion I6 of the lower member I5 and which disk20 issorewed onto the threaded lower end of the reduced portion I3a of the piston rod. It will be understood that the grooves I8 and I9 with the disks I4 and 20 provide :passageways extending from the opposite sides of the piston to the central part of the members I5 now to be described.

The members I5 inwardly of `the cup-shaped portions I6 ythereof are provided with sleeve portions 2I of reduced diameter so that the outer circumference of the sleeve portions is spaced radially inwardly from the inner surface of the working cylinder II. The sleeve portions 2I of the members I5 abut each other in end-to-end relationship and at their abutting ends are provided With inwardly extending shoulders 22 from which radially and inwardly project a plurality of circularly spaced lugs 23 which engage the reduced portion I3a of the piston rod. The abutting ends of the members I5 are providedv with cooperating recesses 24 and pins 25 which interengage and hold the members in proper assembled relationship, one set of said recesses and pins being shown in the drawings. The sleeve portions 2I of the members I5 are provided on their circumferences with axially extending circumferentially spaced-grooves 26 which are circumferentially aligned with the grooves I1 on the periphery of the cup-shapedportion I6. The grooves 26 of one member I5 are axially aligned with corresponding grooves 26 on the other member I5. A bleed opening 21 is provided 4in the wall of each sleeve portion 2I, and is located in a groove 26, it being understood that, if desired, additional bleed openings might be provided. The adjacent ends of the members I5 are provided with a plurality of circularly spaced radially extending grooves 28 which communicate with the grooves 26 and alternate with the lugs 23. Hence the grooves 28 are in communication with the interiors of the sleeve portions 2I of the members I5 by a plurality of axially extending passages 29 dened by the exterior of the reduced mally maintain said valves seated. It will be understood that different strength springs 3I may be used as desired to obtain diierent shock absorber characteristics,

Carriers 32 are slidable on the sleeve portions 2I of the members I5 and said carriers have axially extending portions 33 which slide on `the members I5 and radially .extending portions 34. The carriers 32 mount O rings 35 which bear against the radial arms 34 of the carriers and also against rigid rings 36, it being noted that the O rings 35 are located between the radial portions 34 of the carriers and the rigid rings 36. The free ends of the axial portions 33 of the carriers 32 are provided with a plurality of circularly spaced and circularly extending recesses 31 while said rigid rings 36 iit upon the exteriors of the axial portions 33 of the lcarriers 32. A coil spring 38 surrounds the portions 2l of the members I5 and has its opposite ends abutting against the radially extending portions 34 of the carriers 32, wherefor said spring 38 functions to maintain both carriers, O rings and rigid rings seated against the shoulders provided by the cup-shaped portions I6 of the members I5 and in a position wherein the O rings 35 seal the piston as a piston packing and close off passage of oil through the grooves I1 on the periphery of the cup-shaped portions I6 of the members I5. The spring load imposed by the spring 38 is predetermined to suit different shock yabsorber characteristics desired and the springs 38 and 3I will be correlated as to relative strengths to produce predetermined shock absorber characteristics, it being understood that in some instances the spring 3I may produce a greater load than the spring 38 and vice versa, according to the characteristics desired.

Assuming that the piston commences to move on the impact stroke, i. e., the down stroke, from the position shown in Fig. 1 to the position shown in Fig. 2, pressure will be built up in the working cylinder beneath the piston and this pressure will act on the lower rigid ring 36, the lower O ring 35 and the lower carrier 32. At rst the pressure acting on the lower rigid ring 36 may simply compress the lower O ring 35, moving the rigid ring slightly, wherefor there will be a slight bleed of oil from the lower set of passages, I1 beneath the lower rigid ring 36 through the recesses 31 of the carrier and into the grooves 26, from whence it can ow to the opposite or upper side of the piston through the bleed opening 21 in the upper member I5. As the pressure beneath the piston increases beyond the load of the spring 38 the lower rigid ring 36, lower O ring 35 and vlower carrier 32 will move axially upwardly relative to the piston from the position shown in Fig. 1 to the position shown in Fig. 2, thus permitting a relatively free flow of oil from beneath the piston through the lower set of peripheral grooves or passages il and into the axially extending grooves 2E of the sleeve portions 2| of the members l5, The oil thus flowing into the grooves 25 can bleed through. the upper bleed opening 2 to the other sier, of the piston as indicated by the arrows in Fig. 2. As soon as the pressure of the oil in the axial grooves 25 and in the radial grooves 25 and the axial grooves 29 reaches the point where it overcomes the load of the upper spring the upper sleeve Valve 3i) moves from its seat as shown in Fig. 2 to the position shown in 3, at which latter time a relatively irse iiow ci oil occurs from one side of the piston to the other, said flow being indicated by the arrows in Fig. 3. It will be understood that at this time the lower sleeve valve 3Q remains seated, inasmuch as it is held against its seat by load of the lower spring 3i and the pressure of the oil in the working cylinder beneath the piston. It will be understood that the operation of the valves, i. e. the lower ring 35, and the upper sleeve valve 39) during the downward or impact stroke of the piston .is similar to the order of operation of the upper 0 ring 35i and the lower sleeve valve during the upward or recoil stroke of the piston and therefore detailed description of the order and mode of operation of these valves during the recoil stroke need not be set forth in detail. l

From the explanation thus far it wii?. be seen that various shock absorber ci... actor" istics for both the impact and recoil strokes of the piston can be obtained by using predetermined relative strengths with respect to the springs 3l and 38. Also the spring 3l ei the upper sleeve valve 3B may be oi a strength than the spring 3l for the lower sleeve valve 3l) to get different operative characteristics for the impact and recoil strokes. T n addition, it will be apparent that a wide range of bleed may be obtained by varying the size and the number of the bleed openings 2l. inasmuch as each 0 ring valve and its cooperating sleeve valve are arranged in series and successively function, an expansion space is provided between such valves which produces a reduction in pressure of the oil flowing from one side of the piston to the other side thereof and hence lessens any hissing noise occasioned by the flowing oil and provides for a more quietly operating shock absorber. It will also be observed that the members l5 are symmetrical and hence the piston can be assembled from any two members I5 together with the identical carriers 32, 0 rings 35, rigid rings 36 and sleeve valves 30. This produces a shock absorber which can be economically manufactured and assembled.

Although a preferred embodiment of the invention has been illustrated and described herein, it will be understood that the invention is susceptible of various modications and adaptations within the scope of the appended claims.

Having thus described my invention, I claim:

1. In a iluid shock absorber of the character described, a working cylinder and a piston reciprocable therein and comprising a piston body formed of a pair of symmetrical members arranged in reverse relationship to each other and having portions spaced apart longitudinally or" the cylinder and slidable therein, said members having sleeve portions intermediate the iirstnamed portions and abutting each other and spaced radially inwardly from said working cylinder to provide an intermediate annular space, a piston rod passing through said members, means on said rod securing said members in assembled relationship thereon, said first-mentioned portions of said members being provided on their peripheries with longitudinally extending grooves communicating with said intermediate space and with the working cylinder at the opposite sides of the piston, primary vaive means movable on said sleeve portions, spring means acting on said primary valve means to normally maintain the same seated against said rstmentioned portions to close said peripheral passages, passages in said sleeve portions extending from the said intermediate space to the interiors of said sleeve portions, secondary valve means within said sleeve portions, and independent spring means acting on said secondary valve means to maintain the saine seated to close said last-mentioned passages.

2. A shock absorber as defined in claim l and wherein said primary valves comprise carriers having cylindrical portions slidable on the sleeve portions of said members and provided with radially outwardly extending iianges, 0-rings on said carriers, while said first named spring means comprises a single coil spring located in said intermediate space and surrounding said sleeve portions of said members and having its opposite ends abutting the flanges oi said carriers.

3. A shock absorber as defined in claim i and wherein said secondary valve means comprises a sleeve-like valve member within the sleeve portion of each of said symmetrical members and slidable on said piston rod and provided with a radial flange.

4. A shock absorber as defined in claim 1 and wherein said sleeve portions of said symmetrical members are provided on their circumferences with circularly spaced longitudinally extending grooves, said sleeve portions each being provided with a bleed opening located in one of said grooves and communicating with the interior of the sleeve portion beyond the secondary valve means therein.

WILLIAM G. PATRIQUIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,225,986 Glezen Dec. 24, 1940 2,379,750 Rossman July 3, 1945 2,497,972 Beecher Feb. 21, 1950 

